I. Field of the Invention
The present invention relates to wireless telecommunications. More particularly, the present invention relates to a novel and improved method and apparatus for automatically selecting a data service based on the data being transmitted.
II. Description of the Related Art
The EIS (Electronics Industry Association) and the TIA (Telecommunications Industry Association, 2001 Pennsylvania Avenue, N.W., Washington, D.C. 20006) are industry groups responsible for setting standards to ensure compatibility between computer, telecommunications, and other information processing systems. In accordance with this responsibility, the EIA and TIA have established the IS-99 data services standard for modem emulation data services and the IS-657 data service standard for packet data service. Packet data service provides transport layer packet transmission capability into a packet based network such as the internet. Modem emulation data service provides a dedicated connection to a receiving digital system, and the modulation of digital data into tones in accordance with the use of a standard modem or fax. Modem emulation service also provides for the interpretation and processing of "AT" commands, which are used to control the configuration and processing of the conversion of the digital data into tones. The AT command set is well known in the art, and is defined by the use of the ASCII prefix "AT", in either lower or upper case, followed by anyone of a set of other predefined codes. These other predefined codes include the ASCII characters "DT", either lower or upper case, followed by a telephone number which causes a telephone call to be initiated.
For wireless telecommunication service subscribers who need to connect to a variety of data networks and systems, some of which require a packet based connection and other of which require a modem based connection, it is desirable to have both packet data service and modem emulation data service in a single wireless subscriber unit or cellular telephone. Therefore, providing both packet data service and modem emulation data service in a single wireless subscriber unit increases the usefulness of a wireless subscriber unit, and of the associated wireless telecommunications system. Providing both modem emulation and packet data service, however, also makes it necessary to determine and select the proper type of service for each communication initiated. This determination and selection process can be inconvenient for many users of wireless data communication services, who are often operating in highly mobile environments and switch from one type of service to another in rapid succession. Additionally, many users do not understand the difference between the two types of network connections, and will therefore have trouble selecting the proper type of service for a given communication. This reduces the usefulness of supplying multiple types of data service from a single wireless subscriber unit. Therefore, there is a need for an improved method and apparatus for automatically determining and selecting the desired data service so that a digital connection can properly be established for a variety of communications.